Stable sulfur isotope ratios of the gases from Mt. Sakurajima and Satsuma-Iwojima volcanoes - Assessment of volcanic sulfur on rainfall sulfate in Kagoshima Prefecture

Stable sulfur isotope ratios of SO2 emitted from active volcanoes such as M t. Sakurajima and Satsuma-Iwojima were determined in relation to the projec t clarify source of sulfur in acidic and oxidative compounds in East Asia. The delta(34)S of SO2 were +10.1 to + 13.5 parts per thousand and +3.2 to 8.4 parts per thousand at Satsuma-Iwojima and Mt. Sakurajima, respectively. We reported the delta(34)S values for Mt. Sakurajima for the first time, b ut it should be noted that the gas samples were collected at station about 3 km away from fumarole. Nevertheless the delta(34)S values of Mt. Sakuraji ma volcano were similar to those from Mt. Use, Mt. Tarumae, Mt. Kuju-Iwoyam a and Mt. Aso for which gas samples directly collected from fumarole. The delta(34)S values of sulfate in wet deposition collected at Mt. Shibi a nd Yorita, located approximately 50 km northwest of Mt. Sakurajima volcano, varied with time, contribution of the different sources of sulfur to these two sampling localities. Wet deposition samples from Mt. Shibi were consid ered to be more influenced by Mt. Sakurajima emission than Yorita, which wa s rather affected by continental anthropogenic emission.